Search Results (218)

Background: Proprotein convertase subtilisin/kexin type 9 inhibitor (PCSK9i) has been reported to exhibit anti-neoplasm effects. However, the specific impacts remain uncertain. This study aims to evaluate the association between PCSK9i and the risk of neoplasm. Methods: Randomized controlled trials (RCTs) comparing PCSK9i with other lipid-lowering drugs or placebo in patients, which reported neoplasm events, were included. Data were sourced from PubMed, Embase, Web of Science, the Cochrane Central Register of Controlled Trials, and the Clinicaltrial.gov website from the inception to June 2024. The primary endpoint was the association between PCSK9i and the risk of overall neoplasm events. Results: A total of 37 RCTs with 108,430 participants were included. PCSK9i treatment was associated with a lower risk of neoplasm compared to non-users (RR = 0.92, 95% CI, 0.85 to 0.99, I² = 0%). Subgroup analysis revealed a more prominent risk reduction of overall neoplasm in studies with female-dominant populations (male percentage < 50%, RR = 0.47, 95% CI, 0.27 to 0.82, I² = 0%), with a significant subgroup differences (p = 0.02). Meta-regression analysis also suggested that the lower percentage of males was associated with a decreased risk of neoplasms (β = 0.018, 95% CI, 0.0063, 0.031, p = 0.002). Meanwhile, the decreased risk of neoplasms was independent of LDL-c reduction. Conclusions: PCSK9i therapy was associated with reduced risk of overall neoplasm, especially in female-dominant populations. The benefits for lower risk of neoplasm with PCSK9i treatment were independent of LDL-c reduction. Full article

Cardiotoxicity related to anthracyclines and trastuzumab represents a significant clinical challenge in cancer therapy, often limiting treatment efficacy and patient survival. The underlying mechanisms of cardiotoxicity involve the activation of NLRP3 and the MyD88-dependent signaling pathway. Proprotein convertase subtilisin/kexin type 9 inhibitors (PCSK9i), such as inclisiran, are known for their lipid-lowering effects, but emerging data indicate that they may also exert pleiotropic benefits beyond cholesterol reduction. This study investigates whether inclisiran can mitigate the cardiotoxic effects of anthracyclines and trastuzumab through reduction of NLRP3 activation and MyD88 signaling, independently of its effects on dyslipidemia. Human induced pluripotent stem cell-derived cardiomyocytes (hiPSC-CMs) were exposed to subclinical concentrations of doxorubicin (1 µM) and trastuzumab in sequential therapy (200 nM), alone or in combination with inclisiran (100 nM) for 24 h. After the incubation period, we performed the following tests: determination of cardiomyocytes apoptosis, analysis of intracellular reactive oxygen species, lipid peroxidation products (including malondialdehyde and 4-hydroxynonenal), intracellular mitofusin-2 and Ca⁺⁺ levels. Troponin and BNP were quantified through selective ELISA methods. A confocal laser scanning microscope was used to study cardiomyocyte morphology and F-actin staining after treatments. Moreover, pro-inflammatory studies were also performed, including the intracellular expression of NLRP-3, MyD-88 and twelve cytokines/growth factors involved in cardiotoxicity (IL-1α, IL-1β, IL-2, IL-4, IL-6, IL-10, IL-12, IL17-α, IFN-γ, TNF-α, G-CSF, GM-CSF). Inclisiran co-incubated with doxorubicin and trastuzumab exerts significant cardioprotective effects, enhancing cell viability by 88.9% compared to only DOXO/TRA treated cells (p < 0.001 for all). Significant reduction of oxidative stress, and intracellular levels of NLRP-3, MyD88, IL-1α, IL-1β, IL-6, IL-12, IL17-α, TNF-α, G-CSF were seen in the inclisiran group vs. only DOXO/TRA (p < 0.001). For the first time, PCSK9i inclisiran has been shown to exert significant anti-inflammatory effects to reduce anthracycline-HER-2 blocking agent-mediated cardiotoxicity through NLRP-3 and Myd-88 related pathways. The overall conclusions of the study warrant further investigation of the use of PCSK9i in primary prevention of CTRCD in cancer patients, independently from dyslipidemia. Full article

Background: The advent of newer pharmacological agents, particularly proprotein convertase subtilisin/kexin type 9 (PCSK-9) inhibitors, in combination with conventional lipid-lowering treatments, has allowed for the significant lowering of low-density lipoprotein cholesterol (LDL-C). However, it is unclear if very low LDL-C levels achieved with the use of PCSK-9 inhibitors are associated with increased adverse events that may outweigh potential benefits. Methods: A systematic search of PubMed, Medline, and Cochrane databases was conducted from their inception to 21 February 2025, for randomized controlled trials (RCTs) reporting clinical outcomes with intensive lipid-lowering treatment with PCSK-9 inhibitors leading to very low (<40 mg/dL) LDL-C levels vs. a control group with higher LDL-C levels. The outcomes of interest included the incidence of major adverse cardiovascular events (MACEs), neurocognitive disorders, diabetes mellitus, muscle disorders, any adverse events, events leading to drug discontinuation, cataract, hepatobiliary disorders, and cancer. Random effects meta-analysis models were used to calculate the pooled incidence and odds ratio (OR) with 95% confidence intervals (Cis). Results: A total of six RCTs with 52,951 patients (11,209 very low LDL-C, and 41,742 control) met the inclusion criteria. Compared with patients in the control arm, very low LDL-C was associated with a reduction in MACEs (OR = 0.76, 95% CI: 0.64, 0.89; p < 0.01; I² = 44.8%). The incidence of most safety outcomes including neurocognitive disorders, diabetes mellitus, muscle disorders, any adverse events, events leading to drug discontinuation, cataract, hepatobiliary disorders, and cancer were comparable between the very low LDL-C and control groups. Conclusions: Very low LDL-C values following intensive lipid-lowering with PCSK-9 inhibitors are associated with a major reduction in cardiovascular events without any significant increase in serious side effects. Full article

Background: Colorectal cancer (CRC) is among the most prevalent and lethal cancers globally, with liver metastasis representing the leading cause of CRC-related mortality. Proprotein convertase subtilisin/kexin type 9 (PCSK9) has recently gained attention due to its overexpression in colorectal tumor tissues and its potential role in driving metastatic progression. This aims to investigate the involvement of PCSK9 in the liver metastatic niche, focusing on its effects on liver sinusoidal endothelial cells (LSECs), key components of the liver microenvironment. Methods: LSECs were stimulated with conditioned media derived from differentiated colorectal cancer cells and cancer stem cells (CSCs), the latter generated by reprogramming SW620 and CT26 cell lines. RNA sequencing was used to profile gene expression in LSECs. PCSK9 mRNA and protein levels were quantified by qPCR and Western blotting, respectively. PCSK9 expression in CRC liver metastases was evaluated by immunofluorescent staining. Results: PCSK9 was detected in both human and murine LSECs and significantly upregulated following exposure to CSC-conditioned media. Immunofluorescent staining confirmed PCSK9 expression in LSECs within CRC liver metastases. Total RNA sequencing revealed that a pre-treatment of LSECs with the PCSK9 inhibitor PF-06446864 prior to CSC stimulation seems to reduce the expression of microRNAs linked to cell migration and proliferation. Functional assays demonstrated that CSC-conditioned media enhanced LSEC proliferation and migration, effects reversed by PCSK9 inhibition. Conclusions: PCSK9 promotes the activation of LSECs in response to colorectal CSCs, contributing to a pro-metastatic phenotype. These findings highlight PCSK9 as a potential therapeutic target in colorectal liver metastasis. Full article

Background/Objectives: Hypercholesterolemia, accompanied by vascular inflammation, leads to the premature initiation and progression of atherosclerosis, and both are considered nowadays as well-established cardiovascular (CV) risk factors. For several years, proprotein convertase subtilisin/kexin type 9 inhibitors (PCSK9is), drugs that reduce the degradation of the receptors for low-density lipoprotein cholesterol (LDLRs), have appeared to be a very efficient lipid-lowering therapy among patients with complications resulting from atherosclerotic cardiovascular disease (ASCVD). Previous studies showed that drugs used to fight hypercholesterolemia (predominantly statins) have significant pleiotropic effects, including anti-inflammatory effects. To date, data on the potential impact of PCSK9 inhibitors, especially inclisiran, on the course of inflammation is still lacking. Therefore, we conceived a study to evaluate the effects of inclisiran on the markers of subclinical inflammation (e.g., pentraxin 3 (PTX3), interleukin-18 (IL-18), and soluble cluster of differentiation 40 ligand (CD40L)) and compared their magnitude in patients at high CV risk, with and without established heterozygous familial hypercholesterolemia (HeFH). Methods: A total of 24 patients at high cardiovascular risk, according to European Society of Cardiology (ESC) guidelines, with or without concomitant HeFH diagnosed using Dutch Lipid Clinic Network (DLCN) criteria, were enrolled in this study. Lipid concentrations and levels of subclinical inflammatory markers of atherosclerosis were measured at the beginning and after 3 months of therapy. Results: After three months of therapy with inclisiran, a statistically significant reduction included total cholesterol (TC): study group 1: from 287.6 ± 94.15 to 215.2 ± 89.08 [mg/dL], p = 0.022 and study group 2: from 211.71 ± 52.72 to 147.64 ± 55.44 [mg/dL], p < 0.001, and low-density lipoprotein cholesterol (LDL-c): study group 1: from 180.79 ± 73.33 to 114.65 ± 71.54 [mg/dL], p = 0.031 and study group 2: from 129.62 ± 46.75 to 63.39 ± 43.6 [mg/dL], p < 0.001. Moreover significant drops were observed in concentrations of PTX3: study group 1: from 1336.33 ± 395.15 to 1121.75 ± 351.17 [pg/mL], p = 0.013 and study group 2: from 1610.76 ± 537.78 to 1376.92 ± 529.19 [pg/mL], p = 0.017), and IL-18: study group 1: from 11.89 (9.72–13.98) to 9.15 (8.62–10.06) [pg/mL], p = 0.005 and study group 2: from 11.58 (10.87–16.97) to 9.65 (8.43–10.95) [pg/mL], p = 0.003). There were no significant changes in the levels of sCD40L. Conclusions: This study confirmed the ability of inclisiran to reduce LDL-c levels in patients at high cardiovascular risk just after one dose of the drug. Furthermore, it appeared that beyond its lipid-lowering effect, the drug may also affect some inflammatory processes involved in the initiation and progression of atherosclerosis. Full article

Background: Patients with chronic kidney disease (CKD) face an elevated risk of cardiovascular disease (CVD), particularly those with estimated glomerular filtration rate (eGFR) <30 mL/min/1.73 m². Aims: To assess low-density lipoprotein cholesterol (LDL-C) values and the proportion of pre-dialysis patients achieving national and international targets. Methods: This was a retrospective audit (May–October 2024) of 272 patients aged >18 years attending pre-dialysis clinic (estimated glomerular filtration rate <30 mL/min/1.73 m²) at the Renal Unit, Birmingham Heartlands Hospital. Data on age, sex, ethnicity, body mass index, smoking status, CVD status, hypertension, diabetes, lipids (including LDL-C using the Friedewald and Sampson algorithms) and lipid-lowering therapy were collected from the hospital electronic records. Statistical analyses evaluated factors that were associated with LDL-C (linear/multiple regression) and statin therapy (Chi square). Results: The median (interquartile range) calculated LDL-C values were 2.2 (1.7–2.8) mmol/L and 2.3 (1.7–2.9) mmol/L using the Friedewald and Sampson algorithms respectively. Age and statin therapy were independently associated with LDL-C. Using the Friedewald algorithm, 83.8%, 70.6% and 60.3% did not achieve LDL-C targets of 1.4 mmol/L, 1.8 mmol/L and 2.0 mmol/L respectively, these figures were higher when the Sampson algorithm was applied. Only 18 and 3 of the patients were on ezetimibe and inclisiran respectively, whilst not a single patient was on bempedoic acid or proprotein convertase subtilisin/kexin type 9 inhibitors. Conclusion: Our data highlight deficiencies in the management of LDL-C in advanced CKD. We would recommend greater awareness of LDL-C targets and the use of combination lipid-lowering therapy following optimisation of statin therapy. Full article

Background: The “fast track” addition (within 48 h) of proprotein convertase subtilisin/kexin type 9 inhibitors (PCSK9i) to the optimized oral lipid-lowering therapy (LLT) during hospitalization for acute coronary syndrome (ACS) has been shown to rapidly achieve the low-density lipoprotein cholesterol (LDL-C) therapeutic targets. However, so far, its efficacy in real-world settings remains understudied. Methods: We retrospectively analyzed 128 ACS patients treated at our center, comparing “PCSK9i fast track” use within 48 h to standard “stepwise” LLT. Lipid levels and incidence of major adverse cardiovascular events (MACEs) were evaluated at 30 and 180 days. Results: The “PCSK9i fast track” group achieved significantly lower LDL-C levels at 30 days (41.5 ± 27.5 vs. 85.6 ± 35.9 mg/dL, p < 0.001) and 180 days (29.6 ± 21.0 vs. 59.0 ± 32.4 mg/dL, p < 0.001). Recommended LDL-C targets (<55 mg/dL) were met by 88.3% of the “PCSK9i fast track” group at 180 days, compared with 61.9% of controls (p < 0.001). No significant differences in MACEs were observed between groups. No adverse effects from PCSK9i use were noted. Conclusions: The “PCSK9i fast track” strategy was safe and effective in achieving LDL-C targets more rapidly than conventional approaches in real-world ACS patients. Full article

Introduction and Objectives: Familial hypercholesterolemia (FH) is an autosomal dominant genetic disorder of lipid metabolism that is characterized by elevated low-density lipoprotein cholesterol (LDL-C) levels and a high risk of atherosclerotic cardiovascular disease. Familial hypercholesterolemia is typically caused by mutations in the LDL receptor gene (LDLR), although other alterations may be found. The aim of this study was to perform a genetic study on a population identified through a new population-based diagnostic screen program for FH. Methods: Genetic variants in LDLR, apolipoprotein B (APOB), apolipoprotein E (APOE), proprotein convertase subtilisin/kexin type 9 (PCSK9), signal transducing Adaptor Family Member 1 (STAP1), low density lipoprotein receptor adaptor protein 1 (LDLRAP1) and lipase A, and lysosomal acid type lipase A (LIPA), as well as a genetic risk score, were evaluated in 84 individuals with a clinical diagnosis of FH based on the Dutch Lipid Clinics Network criteria (DLCN ≥ 6). These individuals were selected from a cohort of 752 patients with an abnormal lipid profile, obtained by screening existing centralized analytics. Results: A clinical diagnosis of FH was established in 17.9% of the patients evaluated, with mean LDL-C levels of 305.7 mg/dL (95% CI 250.4–360.9). Genetic variants were detected in 70.2% of these patients, with 50 different mutations identified, mainly in the LDLR. The most frequent pathogenic variants were c.1342C>T and c.313+1G>C. Null variants exhibited a more severe phenotype, and the risk score indicates that patients carrying genetic alterations have a 42% higher risk of developing cardiovascular disease. Conclusions: A high rate of genetic alterations was detected in patients with severe FH. In most cases, the phenotypic findings did not predict the genetic results, which provide important information regarding the cardiovascular risk of patients. Full article

Cardiovascular–kidney–metabolic (CKM) syndrome represents a complex interplay between cardiovascular disease (CVD), chronic kidney disease (CKD), and metabolic disorders, significantly impacting cancer patients. The presence of CKM syndrome in cancer patients not only worsens their prognosis but also increases the risk of major adverse cardiovascular events (MACE), reduces quality of life (QoL), and affects overall survival (OS). Furthermore, several anticancer therapies, including anthracyclines, tyrosine kinase inhibitors, immune checkpoint inhibitors, and hormonal treatments, can exacerbate CKM syndrome by inducing cardiotoxicity, nephrotoxicity, and metabolic dysregulation. This review explores the pathophysiology of CKM syndrome in cancer patients and highlights emerging therapeutic strategies to mitigate its impact. We discuss the role of novel pharmacological interventions, including sodium-glucose cotransporter-2 inhibitors (SGLT2i), proprotein convertase subtilisin/kexin type 9 inhibitors (PCSK9i), and soluble guanylate cyclase (sGC) activators, as well as dietary and lifestyle interventions. Optimizing the management of CKM syndrome in cancer patients is crucial to improving OS, enhancing QoL, and reducing MACE. By integrating cardiometabolic therapies into oncologic care, we can create a more comprehensive treatment approach that reduces the burden of cardiovascular and renal complications in this vulnerable population. Further research is needed to establish personalized strategies for CKM syndrome prevention and treatment in cancer patients. Full article

Background/Objectives: Proprotein convertase subtilisin/kexin type 9 (PCSK9) regulates serum cholesterol levels and inflammation, both of which are dysregulated in inflammatory bowel disease (IBD). Free cholesterol (FC) and the various types of cholesteryl ester (CE) have different functions in the body. However, it is not yet known whether these lipids undergo parallel changes in male and female patients with active IBD, nor whether PCSK9 correlates with these lipids and disease severity in either sex. The present study measured the serum levels of PCSK9, FC, and 15 CE species in IBD patients, focusing on the associations of these molecules with sex, each other, and with disease severity. Methods: The serum PCSK9 levels of 80 IBD patients (42 males and 38 females) and 24 controls (12 males and 12 females) were measured by enzyme-linked immunosorbent assay. In addition, FC and 15 CE species levels of 53 randomly selected IBD patients and 16 controls were determined by direct flow injection analysis (FIA) using a high-resolution hybrid quadrupole-orbitrap mass spectrometer (FIA-FTMS). Results: Serum PCSK9 levels in controls and IBD patients were comparable and did not correlate with disease severity in IBD patients. There was no discernible difference in serum PCSK9, FC, and CE levels between patients with Crohn’s disease (CD) and those with ulcerative colitis (UC). FC and almost all CE species decreased in male patients with active IBD but were not related to disease severity in the female patients. The decrease in different CE species in male IBD patients with diarrhea compared to those with normal stool consistency appears to be related to IBD severity. Bile acids regulate serum cholesterol levels, and FC and CE levels were positively correlated with fecal levels of secondary bile acids in the patients with UC but not CD. This association also existed in male UC patients and could not be evaluated in women due to the small sample size. Conclusions: In active IBD, a reduction in FC and almost all CE species was observed only in males, while serum PCSK9 levels remained within normal ranges in both sexes. It can be hypothesized that blocking PCSK9 may further reduce serum cholesterol levels, which may have adverse effects in male patients with active IBD. Full article

Background and Objectives: Fatty Liver Disease is a major health problem worldwide. We can distinguish liver steatosis as non-associated or associated with chronic/acute alcohol consumption. These two entities share similar stages ranging from hepatic fat storage (namely, steatosis) to inflammation, necrosis, and fibrosis until hepatocellular carcinoma (HCC). Over time, “Metabolic Associated Fatty Liver Disease” (MAFLD) has replaced nonalcoholic fatty liver disease (NAFLD) nomenclature and has included cardiometabolic criteria in these patients definition. Thus, obesity, type 2 diabetes mellitus (T2DM), hypertension, and dyslipidemia are MAFLD features and are of the metabolic syndrome. Importantly, there is not a specific treatment for MAFLD, but there are therapeutic strategies that act on metabolic dysfunction related to MAFLD. They can reduce the progression of liver fibrosis and its complications. Materials and Methods: For all these reasons, we conducted a narrative review of the literature, and we focused on metabolic dysfunction related to MAFLD, with a special regard for cholesterol metabolism. Results: MAFLD is a recently redefined condition that better describes the metabolism derangement responsible for fatty liver disease. This distinguishes MAFLD from NAFLD. In fact, the diagnostic criteria for MAFLD require the presence of liver steatosis together with at least one of the following: obesity, T2DM, or evidence of metabolic disorder such as hypertriglyceridemia, low high-density lipoprotein cholesterol, or hypertension. As a result, MAFLD is closely linked to an increased cardiometabolic risk. Current therapeutic approaches can be used to reduce this risk, focusing on lifestyle interventions and pharmacological strategies. Several treatments in patients diagnosed with MAFLD are mainly cholesterol-lowering remedies. Among these, Pro-protein Convertase Subtilisin/Kexin type 9 inhibitors (PCSK9i) show the most promising efficacy profile but data on liver fibrosis are lacking. Agonists of GLP-1 receptor, Sodium-glucose cotransporter-2 inhibitors (SGLT2i) and Dipeptidyl Peptidase-4 inhibitors (DPP-4i) have a “ multi-hit “ action allowing their use also in diabetic patients with MAFLD. Conclusions: Lifestyle modifications, some nutraceuticals, statins, incretins, and PCSK9i have changed the natural course and significantly improved the cardiometabolic outcomes of MAFLD. Emerging cholesterol-lowering drugs, such as Bempedoic acid, can overcome low compliance to statins’ use and their controversial effect on liver fibrosis. Finally, medications targeting insulin resistance allow for strategic interventions of the convoluted pathophysiology of MAFLD in multiple steps, with the potential to reduce liver steatosis, inflammation, and necrosis and, sometimes even to reverse liver fibrosis. Full article

Proprotein convertase subtilisin/kexin type 9 (PCSK9) has emerged as a novel target for reducing low-density lipoprotein cholesterol. PCSK9 activates the atherosclerosis process through pro-inflammation signaling. Furthermore, the serum level of PCSK9 is positively correlated with mortality in patients with heart failure (HF). Cardiac fibrosis plays a crucial role in the pathophysiology of HF. In this study, we intended to examine whether PCSK9 can increase fibroblast activities and explore what its underlying mechanisms are. Migration, proliferation analyses, and Western blotting were used on human cardiac fibroblasts with and without PCSK9. Alirocumab (a PCSK9 inhibitor, 10 mg/kg/week intra-peritoneally for 28 consecutive days) was treated in isoproterenol (100 mg/kg, subcutaneous injection)-induced HF rats. PCSK9 (50, 100 ng/mL) increased proliferation, myofibroblast differentiation capability, and collagen type I production. Compared with control cells, PCSK9 (100 ng/mL)-treated cardiac fibroblasts showed higher nucleotide-binding domain (NOD)-like receptor protein 3 (NLRP3), interleukin (IL)-1, myofibroblast differentiation, and collagen production capabilities, which were attenuated by MCC950 (an NLRP3 inhibitor, 100 μmol/L). PCSK9 upregulated Myd88 and NF-κB signaling, which were reduced by TAK242 (a toll-like receptor (TLR) 4 inhibitor, 10 μmol/L). Moreover, alirocumab significantly improved left ventricular systolic function and attenuated fibrosis in HF rats. In conclusion, PCSK9 upregulates NLRP3 signaling and the profibrotic activities of cardiac fibroblasts through the activation of TLR4/Myd88/NF-κB signaling. Full article

Metabolic diseases like obesity and diabetes are on the rise, and therapies with biomacromolecules (such as proteins, peptides, antibodies, and oligonucleotides) play a crucial role in their treatment. However, these drugs are traditionally injected. For patients with chronic diseases (e.g., metabolic diseases), long-term injections are accompanied by inconvenience and low compliance. Oral administration is preferred, but the delivery of biomacromolecules is challenging due to gastrointestinal barriers. In this article, we introduce the available biomacromolecule drugs for the treatment of metabolic diseases. The gastrointestinal barriers to oral drug delivery and strategies to overcome these barriers are also explored. We then discuss strategies for alleviating metabolic defects, including glucose metabolism, lipid metabolism, and energy metabolism, with oral biomacromolecules such as insulin, glucagon-like peptide-1 receptor agonists, proprotein convertase subtilisin/kexin type 9 inhibitors, fibroblast growth factor 21 analogues, and peptide YY analogues. Full article

Pharmaceutical advancements and an improved understanding of pathophysiology have enabled innovative therapies for chronic conditions like dyslipidemia. This condition is marked by abnormalities in lipid homeostasis. Nucleic acid therapeutics, including antisense oligonucleotides and small interfering RNAs, are novel management strategies that silence genes by targeting mRNA. Antisense oligonucleotides modify mRNA to inhibit protein production, whereas small interfering RNAs induce mRNA degradation via the RNA-induced silencing complex (RISC), thus offering promising treatments for dyslipidemia and atherosclerotic cardiovascular disease. Chemical modifications improve their stability and mRNA targeting. RNA-based therapies targeting PCSK9, Lp(a), ApoC-III, and ANGPTL3 hold transformative potential for treating dyslipidemia effectively. This article discusses the latest data from completed and ongoing trials on RNA therapies for dyslipidemia, including inclisiran, pelacarsen, olpasiran, zerlasiran, lepodisiran, volanesorsen, olezarsen, plozasiran, zodasiran, and solbinsiran. Each therapy targets specific molecules while also significantly impacting other lipid parameters. The promising results of these trials indicate potential improvements in lipid therapy and cardiovascular risk reduction, with ongoing studies expected to further refine the role of the novel RNA-based agents in effective lipid management. Full article

Beyond the regulation of cholesterol metabolism, a number of extrahepatic functions of proprotein convertase subtilisin/kexin type 9 (PCSK9) have been increasingly identified. The main purpose of this study was to verify whether PCSK9 expression in vascular smooth muscle cells (VSMC) is influenced by insulin resistance and high glucose (HG). In cultured rat aortic VSMC from lean insulin-sensitive Zucker rats (LZRs) and obese insulin-resistant Zucker rats (OZRs), a classical animal model of insulin resistance, we evaluated PCSK9 expression with or without the monoclonal antibodies against PCSK9 Alirocumab and Evolocumab or the synthetic PCSK9-binding peptide PEP 2-8. Effects and molecular mechanisms underlying altered PCSK9 expression were evaluated by proliferation and migration assay, reactive oxygen species (ROS) production, and involvement of PKC, NADPH-oxidase, MAPK/ERK-1/2 pathway activation. As a result, we found that, in comparison with LZR, VSMC from OZR showed basal PCSK9 overexpression mitigated by Alirocumab, Evolocumab, PEP 2-8, and the inhibitors of PKC, NADPH-oxidase, and MAPK. The finding of PCSK9 upregulation in VSMC from OZR paralleled with increased ROS production, proliferation, and migration. HG increased PCSK9 expression in VSMC from LZR, but not in OZR, via oxidative stress and with effects reduced by PCSK9 inhibitors. These findings suggest that a dysregulation of PCSK9 in VSMC could be involved in vascular damage in metabolic disorders, such as obesity and diabetes. Full article